1. Field of the Invention
The present invention relates to an information processing system for storing and retrieving information.
2. Description of the Prior Art
Microfilm systems have conventionally been utilized for storing and utilizing a very large amount of information. Microfilms have advantages of human readability, ability for storing non-coded image information, economy, archieval property, high resolving power etc., and are suitable for effectively storing and utilizing filed information increasing year after year since they allow fast input and high-speed copying of a large amount of information.
On the other hand, recent remarkable progress of so-called office automation has stimulated the introduction of computers into the offices and the mutual connection of various devices through communication lines. In order to adapt to such tendency of wider use of computers and communication, the information to be handled should preferably be stored in the form of electrical signals. For this reason much attention is being paid to electronic file systems which store information in the form of electrical signals and have advantages of high-speed retrieval and high-speed transmission which cannot be achievable with the microfilm files.
While the electronic file systems have the above-mentioned advantages and can satisfactorily adapt to the currently progressing trend of office automation, the conventional microfilm systems are unable to adapt to such tendency, particularly in terms of lack of compatibility with the recent office equipment designed to match the trend of computerization.
FIG. 1 shows an example of the conventional microfilm system, or a reader-printer typically utilized for obtaining hard copies. In FIG. 1, the light from a light source 1 is transmitted by a microfilm 2 and a lens 3, and is reflected by a fixed mirror 4. In the use as a reader, a movable mirror 5 is positioned at a, whereby the light reflected by the fixed mirror 4 is projected onto a screen 6 to reproduce the image of the microfilm on said screen. On the other hand, in the use as a printer, the movable mirror 5 is moved to a position b to guide the light reflected by the fixed mirror 4 onto a photosensitive sheet 7, which is then processed in a developing unit 8 and ejected as a hard copy.
However, such process not only requires time but also is associated with an unsatisfactory image quality. In order to improve the image quality there is also proposed to guide the reflected light from the movable mirror 5 at the position b into an ordinary copier to prepare a hard copy. However the drawback of time requirement is not resolved since in any case there is required a procedure of retrieving a desired microfilm from a large file and setting said microfilm on the reader-printer for obtaining a hard copy. Besides, the transmission of the microfilmed information to a distant location can only be made by mailing or by facsimile transmission and cannot in any way adapt to the trend of office automation.
In order to avoid such drawbacks there is proposed a microfilm file as shown in FIG. 2. It is to be noted that the equipment shown in FIG. 2 utilizes microfiches 10 which are stored in a given order in a magazine 9.
For viewing a microfilm frame containing a desired document with such file, an address A is entered through an input device (not shown), for example keyboard. In response to said address A a search unit 11 rotates the magazine 9 and stops it at a selected position. Then a drive mechanism (not shown) takes out the microfiche 10 from the magazine 9 and locates the desired frame. After the desired frame is properly positioned, a light source 12 is turned on and the light therefrom is transmitted through a lens 13, the desired frame of the microfiche 10 and a lens 14 to enter a half mirror 15. The light reflected by said half mirror 15 is transmitted through a lens 16 to project the image of the desired frame onto an optical screen (not shown).
The hard copying or transmission to a distant location of the information displayed on the screen is conducted in the following manner. The light transmitted by the half mirror 15 is converted by a photoelectric converter 17 into electrical signals, which are subjected to signal processing such as digitization and amplification in a signal processor 18 to provide image data D. The photoelectric converter 17 performs scanning in a direction of arrows under the control of a scanning control unit 19, thus converting the image information of the entire frame into the electrical signals. The image data D thus obtained from the desired frame are transmitted to an unrepresented hard copying unit or a facsimile transmitter. Said photoelectric converter 17 is composed for example of a CCD linear sensor. Naturally the scanning drive can be dispensed with if a two-dimensional area senser is employed.
FIG. 3 shows an example of microfilm file employing a microfilm in the form of roll. The structure is essentially same as that shown in FIG. 2, except the driving method for search is somewhat different because the microfilm 20 is contained in a cartridge 21.
The structure shown in FIG. 2 or FIG. 3 enables retrieval, hard copying and transmission at a higher speed, utilizing microfilms either in the roll form or card form represented by microfiches.
FIG. 4 shows an example of an electronic file system, in which a document reader 22, a printer 23, a work station 24 and a memory 26 are connected to a controller 27 to constitute a system. However an index file 25 is connected to the work station 24.
The document reader 22, utilizing for example a charge-coupled device (CCD), raster scans a document to convert the information into electrical signals, which are stored as image data into the memory 26 after suitable processing such as amplification and digitization. In this manner the desired documents can be stored in succession into the memory 26.
It will be evident that the memory 26 should preferably have a capacity as large as possible. For example, in case of an optical disk memory, a disk of 30 cm in diameter can store non-coded information corresponding to about 50 document files, or a small file cabinet. The optical disk can naturally be replaced by an optomagnetic disk. At the storage of a document in the memory 26, the corresponding index is simultaneously memorized in the index file 25.
For obtaining a hard copy of a document stored in the memory 26, a keyword of the desired document is entered through the work station 24. Thus the desired document is read from the memory 26 with reference to the index file 25, and the printer 23 prepares a hard copy of said document.
The printer 23 may be of an electrostatic printer or a laser beam printer. Also the information can be monitored as a soft copy displayed on the work station 24 instead of hard copying.
The controller 27 is used for controlling the entire system, and is provided with interfaces, signal compression/expansion circuits etc. The controller 27 may be independent as shown in FIG. 4 or integral with the document reader 22, printer 23, work station 24 or memory 26.
Such electronic file achieves automatic retrieval within a short period of 2 to 10 seconds in response to the instruction from the work station 24, as a large amount of documents is stored in the form of electrical signals through the document reader 22. Also it is provided with a splendid advantage of information retrieval even immediately after the information recording, since the developing process as required in the microfilm is no longer necessary.
On the other hand, some advantages of the microfilm are inevitably sacrificed. Such losses include a slower input speed caused by the photoelectric conversion through raster scanning instead of one-shot conversion through a lens system in the microfilm system, lack of human readability, lack of possibility of high-speed and economical copying below several hundred copies, lack of proven ability of archival storage over 10 to 20 years in contrast to the proven history of microfilms over 100 years, and lack of ability as legal evidence for which the microfilms are already authorized.
A still larger problem is that the data base and information hitherto accumulated with the microfilms become no longer usable at the introduction of the electronic file. As already explained, the microfilm file and the electronic file have respective advantages. Although the electronic file has more advantages in consideration of the recent trend of office automation, the microfilm system cannot be evidently neglected. There has therefore been desired an information storage adaptable to a comprehensive information processing system making use of the advantages of the electronic file such as the high retrieval speed while fully utilizing the information accumulated in the microfilms.